Would any manned orbital launches to date have been possible (but lower) if they were launched retrograde...

Multi tool use
$begingroup$
Manned launches have always been launched prograde to take advantage of the Earth's rotation velocity boost, and often in order to match the prograde orbit of another spacecraft for rendez-vous.
I wonder if any of the manned orbital launches to date could have reached at least a lower, short-term-stable orbit if launched in a retrograde direction, let's say with an additional 180 degrees inclination, they don't need to be zero-degrees equatorial.
I'm curious if this would have been impossible, or achievable and simply requiring the topping-off existing propellant tanks.
I have read that the launching near the equator gives the rocket more speed, but I wonder if it is at all possible to launch against the rotation.
orbital-mechanics launch physics
New contributor
tom is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
Manned launches have always been launched prograde to take advantage of the Earth's rotation velocity boost, and often in order to match the prograde orbit of another spacecraft for rendez-vous.
I wonder if any of the manned orbital launches to date could have reached at least a lower, short-term-stable orbit if launched in a retrograde direction, let's say with an additional 180 degrees inclination, they don't need to be zero-degrees equatorial.
I'm curious if this would have been impossible, or achievable and simply requiring the topping-off existing propellant tanks.
I have read that the launching near the equator gives the rocket more speed, but I wonder if it is at all possible to launch against the rotation.
orbital-mechanics launch physics
New contributor
tom is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
$begingroup$
Launches from Vandenberg sometimes go westwards to get a polar orbit. These are military recon launches. The shuttle was always launched towards the East.
$endgroup$
– zeta-band
3 hours ago
1
$begingroup$
Related: space.stackexchange.com/q/25849/58
$endgroup$
– called2voyage♦
3 hours ago
$begingroup$
yes, Apollo. All that extra TLI $Delta v$
$endgroup$
– JCRM
2 hours ago
add a comment |
$begingroup$
Manned launches have always been launched prograde to take advantage of the Earth's rotation velocity boost, and often in order to match the prograde orbit of another spacecraft for rendez-vous.
I wonder if any of the manned orbital launches to date could have reached at least a lower, short-term-stable orbit if launched in a retrograde direction, let's say with an additional 180 degrees inclination, they don't need to be zero-degrees equatorial.
I'm curious if this would have been impossible, or achievable and simply requiring the topping-off existing propellant tanks.
I have read that the launching near the equator gives the rocket more speed, but I wonder if it is at all possible to launch against the rotation.
orbital-mechanics launch physics
New contributor
tom is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
Manned launches have always been launched prograde to take advantage of the Earth's rotation velocity boost, and often in order to match the prograde orbit of another spacecraft for rendez-vous.
I wonder if any of the manned orbital launches to date could have reached at least a lower, short-term-stable orbit if launched in a retrograde direction, let's say with an additional 180 degrees inclination, they don't need to be zero-degrees equatorial.
I'm curious if this would have been impossible, or achievable and simply requiring the topping-off existing propellant tanks.
I have read that the launching near the equator gives the rocket more speed, but I wonder if it is at all possible to launch against the rotation.
orbital-mechanics launch physics
orbital-mechanics launch physics
New contributor
tom is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
tom is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 3 hours ago


uhoh
35.9k18126445
35.9k18126445
New contributor
tom is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 3 hours ago


tomtom
616
616
New contributor
tom is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
tom is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
tom is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$begingroup$
Launches from Vandenberg sometimes go westwards to get a polar orbit. These are military recon launches. The shuttle was always launched towards the East.
$endgroup$
– zeta-band
3 hours ago
1
$begingroup$
Related: space.stackexchange.com/q/25849/58
$endgroup$
– called2voyage♦
3 hours ago
$begingroup$
yes, Apollo. All that extra TLI $Delta v$
$endgroup$
– JCRM
2 hours ago
add a comment |
$begingroup$
Launches from Vandenberg sometimes go westwards to get a polar orbit. These are military recon launches. The shuttle was always launched towards the East.
$endgroup$
– zeta-band
3 hours ago
1
$begingroup$
Related: space.stackexchange.com/q/25849/58
$endgroup$
– called2voyage♦
3 hours ago
$begingroup$
yes, Apollo. All that extra TLI $Delta v$
$endgroup$
– JCRM
2 hours ago
$begingroup$
Launches from Vandenberg sometimes go westwards to get a polar orbit. These are military recon launches. The shuttle was always launched towards the East.
$endgroup$
– zeta-band
3 hours ago
$begingroup$
Launches from Vandenberg sometimes go westwards to get a polar orbit. These are military recon launches. The shuttle was always launched towards the East.
$endgroup$
– zeta-band
3 hours ago
1
1
$begingroup$
Related: space.stackexchange.com/q/25849/58
$endgroup$
– called2voyage♦
3 hours ago
$begingroup$
Related: space.stackexchange.com/q/25849/58
$endgroup$
– called2voyage♦
3 hours ago
$begingroup$
yes, Apollo. All that extra TLI $Delta v$
$endgroup$
– JCRM
2 hours ago
$begingroup$
yes, Apollo. All that extra TLI $Delta v$
$endgroup$
– JCRM
2 hours ago
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
The “westward penalty” from Canaveral would be about 800 m/s of delta-v, about 8-9% of the total delta-v requirement to orbit. Most crewed launchers to date have not had that much performance in reserve.
Atlas/Mercury and Titan/Gemini could not have managed it. The boosters were completely expended to reach orbit, and Gemini didn’t have much maneuvering capability.
The low Earth orbit Apollo missions (Apollo 7 and 9) could have reached orbit, and even carried out something like their intended missions.
Apollo 7 was a crewed CSM on a Saturn IB booster. The CSM had substantially more than 800 m/s available, and in fact the “mode IV” abort option would use the CSM as a third stage to reach orbit if the S-IVB second stage failed. Apollo 7 did a lot of orbital maneuvering to test the CSM engine, and that would have had to be cut short if it were going to spend that much fuel on ascent, but a sizable portion of the original mission plan could have been carried out in retrograde.
Apollo 9 was a CSM/LM flight to LEO on a Saturn V; if fully fueled, the third stage would have had around 3000 m/s of delta-v capability (needed for translunar flight), so a much lighter fuel load would suffice to go into retrograde orbit.
I believe any of the Apollo lunar missions could have gone from a retrograde Earth orbit ascent to a lunar flyby without hardware modification, abandoning the LM (or docking and extracting it very quickly) when the S-IVB ran out of fuel and completing the TLI on the CSM’s engine. If the LM wasn’t brought along (as on Apollo 8) and both the S-IVB and CSM were fully fueled, a lunar orbit mission might even have been possible from retrograde LEO.
The space shuttle might have had the capability if little or no payload was carried — I’ll run the numbers once I’m near a bigger computer.
I don’t think the Soyuz or Long March launchers had that sort of performance margin.
$endgroup$
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "508"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
tom is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fspace.stackexchange.com%2fquestions%2f33676%2fwould-any-manned-orbital-launches-to-date-have-been-possible-but-lower-if-they%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
The “westward penalty” from Canaveral would be about 800 m/s of delta-v, about 8-9% of the total delta-v requirement to orbit. Most crewed launchers to date have not had that much performance in reserve.
Atlas/Mercury and Titan/Gemini could not have managed it. The boosters were completely expended to reach orbit, and Gemini didn’t have much maneuvering capability.
The low Earth orbit Apollo missions (Apollo 7 and 9) could have reached orbit, and even carried out something like their intended missions.
Apollo 7 was a crewed CSM on a Saturn IB booster. The CSM had substantially more than 800 m/s available, and in fact the “mode IV” abort option would use the CSM as a third stage to reach orbit if the S-IVB second stage failed. Apollo 7 did a lot of orbital maneuvering to test the CSM engine, and that would have had to be cut short if it were going to spend that much fuel on ascent, but a sizable portion of the original mission plan could have been carried out in retrograde.
Apollo 9 was a CSM/LM flight to LEO on a Saturn V; if fully fueled, the third stage would have had around 3000 m/s of delta-v capability (needed for translunar flight), so a much lighter fuel load would suffice to go into retrograde orbit.
I believe any of the Apollo lunar missions could have gone from a retrograde Earth orbit ascent to a lunar flyby without hardware modification, abandoning the LM (or docking and extracting it very quickly) when the S-IVB ran out of fuel and completing the TLI on the CSM’s engine. If the LM wasn’t brought along (as on Apollo 8) and both the S-IVB and CSM were fully fueled, a lunar orbit mission might even have been possible from retrograde LEO.
The space shuttle might have had the capability if little or no payload was carried — I’ll run the numbers once I’m near a bigger computer.
I don’t think the Soyuz or Long March launchers had that sort of performance margin.
$endgroup$
add a comment |
$begingroup$
The “westward penalty” from Canaveral would be about 800 m/s of delta-v, about 8-9% of the total delta-v requirement to orbit. Most crewed launchers to date have not had that much performance in reserve.
Atlas/Mercury and Titan/Gemini could not have managed it. The boosters were completely expended to reach orbit, and Gemini didn’t have much maneuvering capability.
The low Earth orbit Apollo missions (Apollo 7 and 9) could have reached orbit, and even carried out something like their intended missions.
Apollo 7 was a crewed CSM on a Saturn IB booster. The CSM had substantially more than 800 m/s available, and in fact the “mode IV” abort option would use the CSM as a third stage to reach orbit if the S-IVB second stage failed. Apollo 7 did a lot of orbital maneuvering to test the CSM engine, and that would have had to be cut short if it were going to spend that much fuel on ascent, but a sizable portion of the original mission plan could have been carried out in retrograde.
Apollo 9 was a CSM/LM flight to LEO on a Saturn V; if fully fueled, the third stage would have had around 3000 m/s of delta-v capability (needed for translunar flight), so a much lighter fuel load would suffice to go into retrograde orbit.
I believe any of the Apollo lunar missions could have gone from a retrograde Earth orbit ascent to a lunar flyby without hardware modification, abandoning the LM (or docking and extracting it very quickly) when the S-IVB ran out of fuel and completing the TLI on the CSM’s engine. If the LM wasn’t brought along (as on Apollo 8) and both the S-IVB and CSM were fully fueled, a lunar orbit mission might even have been possible from retrograde LEO.
The space shuttle might have had the capability if little or no payload was carried — I’ll run the numbers once I’m near a bigger computer.
I don’t think the Soyuz or Long March launchers had that sort of performance margin.
$endgroup$
add a comment |
$begingroup$
The “westward penalty” from Canaveral would be about 800 m/s of delta-v, about 8-9% of the total delta-v requirement to orbit. Most crewed launchers to date have not had that much performance in reserve.
Atlas/Mercury and Titan/Gemini could not have managed it. The boosters were completely expended to reach orbit, and Gemini didn’t have much maneuvering capability.
The low Earth orbit Apollo missions (Apollo 7 and 9) could have reached orbit, and even carried out something like their intended missions.
Apollo 7 was a crewed CSM on a Saturn IB booster. The CSM had substantially more than 800 m/s available, and in fact the “mode IV” abort option would use the CSM as a third stage to reach orbit if the S-IVB second stage failed. Apollo 7 did a lot of orbital maneuvering to test the CSM engine, and that would have had to be cut short if it were going to spend that much fuel on ascent, but a sizable portion of the original mission plan could have been carried out in retrograde.
Apollo 9 was a CSM/LM flight to LEO on a Saturn V; if fully fueled, the third stage would have had around 3000 m/s of delta-v capability (needed for translunar flight), so a much lighter fuel load would suffice to go into retrograde orbit.
I believe any of the Apollo lunar missions could have gone from a retrograde Earth orbit ascent to a lunar flyby without hardware modification, abandoning the LM (or docking and extracting it very quickly) when the S-IVB ran out of fuel and completing the TLI on the CSM’s engine. If the LM wasn’t brought along (as on Apollo 8) and both the S-IVB and CSM were fully fueled, a lunar orbit mission might even have been possible from retrograde LEO.
The space shuttle might have had the capability if little or no payload was carried — I’ll run the numbers once I’m near a bigger computer.
I don’t think the Soyuz or Long March launchers had that sort of performance margin.
$endgroup$
The “westward penalty” from Canaveral would be about 800 m/s of delta-v, about 8-9% of the total delta-v requirement to orbit. Most crewed launchers to date have not had that much performance in reserve.
Atlas/Mercury and Titan/Gemini could not have managed it. The boosters were completely expended to reach orbit, and Gemini didn’t have much maneuvering capability.
The low Earth orbit Apollo missions (Apollo 7 and 9) could have reached orbit, and even carried out something like their intended missions.
Apollo 7 was a crewed CSM on a Saturn IB booster. The CSM had substantially more than 800 m/s available, and in fact the “mode IV” abort option would use the CSM as a third stage to reach orbit if the S-IVB second stage failed. Apollo 7 did a lot of orbital maneuvering to test the CSM engine, and that would have had to be cut short if it were going to spend that much fuel on ascent, but a sizable portion of the original mission plan could have been carried out in retrograde.
Apollo 9 was a CSM/LM flight to LEO on a Saturn V; if fully fueled, the third stage would have had around 3000 m/s of delta-v capability (needed for translunar flight), so a much lighter fuel load would suffice to go into retrograde orbit.
I believe any of the Apollo lunar missions could have gone from a retrograde Earth orbit ascent to a lunar flyby without hardware modification, abandoning the LM (or docking and extracting it very quickly) when the S-IVB ran out of fuel and completing the TLI on the CSM’s engine. If the LM wasn’t brought along (as on Apollo 8) and both the S-IVB and CSM were fully fueled, a lunar orbit mission might even have been possible from retrograde LEO.
The space shuttle might have had the capability if little or no payload was carried — I’ll run the numbers once I’m near a bigger computer.
I don’t think the Soyuz or Long March launchers had that sort of performance margin.
answered 1 hour ago
Russell BorogoveRussell Borogove
84k2281362
84k2281362
add a comment |
add a comment |
tom is a new contributor. Be nice, and check out our Code of Conduct.
tom is a new contributor. Be nice, and check out our Code of Conduct.
tom is a new contributor. Be nice, and check out our Code of Conduct.
tom is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Space Exploration Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fspace.stackexchange.com%2fquestions%2f33676%2fwould-any-manned-orbital-launches-to-date-have-been-possible-but-lower-if-they%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
var $window = $(window),
onScroll = function(e) {
var $elem = $('.new-login-left'),
docViewTop = $window.scrollTop(),
docViewBottom = docViewTop + $window.height(),
elemTop = $elem.offset().top,
elemBottom = elemTop + $elem.height();
if ((docViewTop elemBottom)) {
StackExchange.using('gps', function() { StackExchange.gps.track('embedded_signup_form.view', { location: 'question_page' }); });
$window.unbind('scroll', onScroll);
}
};
$window.on('scroll', onScroll);
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
ix42OC3MM0F6MLF7q7EsX1S2FhD7UAQkoDR,wd,ImaMgZKUxAdedg0T4aY3IPXqk
$begingroup$
Launches from Vandenberg sometimes go westwards to get a polar orbit. These are military recon launches. The shuttle was always launched towards the East.
$endgroup$
– zeta-band
3 hours ago
1
$begingroup$
Related: space.stackexchange.com/q/25849/58
$endgroup$
– called2voyage♦
3 hours ago
$begingroup$
yes, Apollo. All that extra TLI $Delta v$
$endgroup$
– JCRM
2 hours ago