Space Rescue Missions and Vehicles

[A_M_Swallow]

The "5.5 Segment Ares I" thread introduced the suspicion that Ares I flights will need a rescue vehicle standing by for a Launch on Need (LON) flight.
http://forum.nasaspaceflight.com/index.php?topic=13498.75

This thread is to allow discussion of:
* the need for LON - including causes of failure and the possibility that reliability makes LON unnecessary,
* failure situations for which a rescue mission is a viable option e.g. following a fuel leak,
* different types of rescue missions and vehicles e.g launch an unmanned spacecraft a week later,
* alternatives such as having consumables at the International Space Station and/or in lunar orbit,
* generalisation of principle, such as a LON LSAM at EML2,
* or possibly needing both consumables and a rescue mission,
* schedule and cost impacts,
* side effects, for instance a larger Vehicle Assembly Building (VAB) may be needed to hold the LON launch vehicle.

[Launch Fan]

The "5.5 Segment Ares I" thread introduced the suspicion that Ares I flights will need a rescue vehicle standing by for a Launch on Need (LON) flight.

Why? There's no need for LON. And it's only misinformed posters who are suggesting it. So what's the point of another thread that's inaccurate?

[cb6785]

Keeping the other one on topic?

[marsavian]

LON is not going to happen as a pre-planned exercise for Cx. However the odds of losing a crew is about 1 in 65 lunar missions according to ESAS. If/when that happens the nature of that loss will be examined to see if some sort of LON would have made a difference. If it would you would then see a need for an Ares V standing by to deliver either a CEV and/or empty LSAM as a catch-all measure.

[jimvela]

LON is not going to happen as a pre-planned exercise for Cx. However the odds of losing a crew is about 1 in 65 lunar missions according to ESAS. If/when that happens the nature of that loss will be examined to see if some sort of LON would have made a difference. If it would you would then see a need for an Ares V standing by to deliver either a CEV and/or empty LSAM as a catch-all measure.

I still contend that a rescue launch is not the answer, pre-positioned survival/escape facilities and supplies are.

A responsive launch of a crew-capable capsule is also an interesting capability that might be a back-pocket item for the emerging players for COTS or space tourism, but that is a distant, distant future type capability.

I'm vigorously opposed to a LON ruleset for any of the exploration missions not using an orbiter.  The money and hassle we piss away would be far better spent on more missions rather than having two launch vehicles always sitting on or near the pad and ready to go at all times.  Ridiculous...

[jimvela]

The parent quoted item has been moved over from the 5.5 Segment Ares I thread...

Please save all your rhetoric and simply point me to the Constellation Program requirement for LON.

Try the high level requirement to minimise the Loss of Crew.

A rescue mission prevents a LOM event becoming a LOC event.
See for some risk definitions.
http://en.wikipedia.org/wiki/Hazard_analysis

Pad Rat is right, there is not any requirement for LON for Cx launches. 

The high level program requirement requirement to reduce LOC doesn't force LON mission planning, and it is ignorant to assert that it does.   

Further, if it were LOC reduction which were the most important requirement driving the mission architecture, the ARES-I launcher would be long, long gone, and a Direct launcher or even more likely something like an EELV with a crew capsule on top would be the new baseline.

In the early stages of a mission beyond LEO, a LOM event almost certainly translates into an abort and reentry by the crew capsule.  The focus there on LOC numbers is a robust and reliable escape/emergency entry contingency for the crew, not an even riskier wait for a ground response mission.

Once an exploration mission leaves LEO for lunar orbit (or beyond), then you're just simply to far away for a rescue launch to get to a capsule so crippled as to present LOC as an imminent threat.  A LON launch does nothing whatsoever to save that crew.

Quoting a wikipedia article tangental to the actual mission design of an exploration system is pedantic at best and a deliberate FUD dodge at worst.

One more time:  Point to any written requirement for Cx mandating LON mission planning.  There is none, and there won't be any, because those whom are competent to design the missions in the first place understand the profound folly and see the LON for what it is- "feeling safer", instead of being safer.

[marsavian]

Once an exploration mission leaves LEO for lunar orbit (or beyond), then you're just simply to far away for a rescue launch to get to a capsule so crippled as to present LOC as an imminent threat.  A LON launch does nothing whatsoever to save that crew.

Look at fig 1-13 in ESAS and you will see that LSAM operations are the biggest risk factor and not CEV ones. If you have an LSAM stranded on the Moon you will need another one pretty sharp. It's very presumptuous to think nothing could be done in *all* circumstances, again experience will tell us what is ultimately needed if at all possible and sadly after an accident not before.

[Jim]

Please save all your rhetoric and simply point me to the Constellation Program requirement for LON.

Try the high level requirement to minimise the Loss of Crew.

A rescue mission prevents a LOM event becoming a LOC event.
See for some risk definitions.
http://en.wikipedia.org/wiki/Hazard_analysis

Quoting wiki just shows that the argument has no basis and shows you have nothing to back you up.  Plus Hazard analysis has nothing to do with this. 

The high level requirements for LOC and LOM numbers are  for one launch.  Not two.

[MrTim]

(snip) Further, if it were LOC reduction which were the most important requirement driving the mission architecture, the ARES-I launcher would be long, long gone, and a Direct launcher or even more likely something like an EELV with a crew capsule on top would be the new baseline.

Wrong. First, there is no discussion about changing the architecture, only about launching a LON Orion in situations where doing so would save a crew. There was no need to pollute the thread with more pro-Direct stuff. Direct could, by some reckoning have worse safety numbers by virtue of having two SRBs in the 1st stage...

In the early stages of a mission beyond LEO, a LOM event almost certainly translates into an abort and reentry by the crew capsule. (snip)

And in such a situation, no LON would be launched. This is obvious.

Once an exploration mission leaves LEO for lunar orbit (or beyond), then you're just simply to far away for a rescue launch to get to a capsule so crippled as to present LOC as an imminent threat.  A LON launch does nothing whatsoever to save that crew.

Again, obvious and an accepted risk. Does not go to the issue as it was being discussed.

Quoting a wikipedia article tangental to the actual mission design of an exploration system is pedantic at best and a deliberate FUD dodge at worst.

Yeah, using Wikipedia as a serious reference is a bit weak, but you need not question the guy's motives...

One more time:  Point to any written requirement for Cx mandating LON mission planning.  There is none, and there won't be any, because those whom are competent to design the missions in the first place understand the profound folly and see the LON for what it is- "feeling safer", instead of being safer.

I'll return the favor and ask that you point to the LON mandates for Skylab (please only include requirements written before the 1st Apollo boilerplate flew). Please also point to the LON mandates and mission plans for STS (but only include those which were written-up before Enterprise made the 1st hop on a 747) These are roughly equivalent for those programs (which both ended-up with LON options) to the point we are at today with Cx.

You are making the same profound error that Jim is making. The discussion was not a purely technical one about whether a LON mission could technically be done, nor was it a question of whether there were formal requirements for LON in the Cx program documents, nor indeed was it a discussion of LON for portions of missions where no such possibility exists. Nobody was engaged in fantasy dreams of saving a crew half-way to Mars or any other lunacy and nobody was dreaming of fantasy technologies like nuclear lightbulbs (which seem to draw less disdain here than an Orion LON); the discussion was related to public tolerance for failing to provide a LON capability for those portions of a mission where one actually could work (such as during ISS missions or the LEO portions of lunar or Mars missions) and then possibly any technical matters related to a realistic LON mission.

Consider the extremely unlikely event of a catastrophic failure in the service module. Do not paper-it over by claiming to have a perfect vehicle where no such failure can happen (humans are not perfect and they do not make perfect machines). Presume the SM is dead (not an unprecedented event... Apollo-on-steroids could well become Apollo-13-on-steroids) and the CM either cannot separate from it or has had its heat shield damaged in the incident. Everybody on this forum appears to agree that Orion will have no self inspection or self repair capabilities, so let's accept that as a given. In such circumstances, the crew may well be alive, but unable to get to ISS and unable to re-enter in that Orion. Does anybody here really insist that NASA's proper response would be to do nothing and permit the crew to perish? Even when the crew might be rescued if only the next Ares I and Orion could be rolled-out and fired? Is there anybody on this site who will seriously assert that the public would be just fine with letting the crew die in a situation where the crew could be saved by a LON mission? What about aborts to ISS? Is there anybody asserting that NASA would not send another Orion to ISS to fetch the crew? (STS flights to get a crew from the ISS are in the category of LON flights, which some here boldly assert are not a part of the Cx program) I believe that NASA would be forced, by public opinion, to at least attempt to save a crew in circumstances where the public would believe a crew could be rescued and I believe that they fail to plan for these contingencies at their peril.

Any argument that no such situation could possibly occur because Orion and Ares will be perfectly safe and redundant is a dodge and best relegated to some other thread along with other fantasy perfect launcher and capsule concepts.

[Jim]

 Even when the crew might be rescued if only the next Ares I and Orion could be rolled-out and fired?

Here is the error.  There isn't another Ares I and Orion available within the lifetime of the stranded Orion on orbit.  The architecture isn't setup to provide this. 
One VAB cell, one MLP, one pad for Ares I.  Ares I launches within week of rollout. (no surge capability)

 MPPF sized for only one Orion at a time.  Ground crews sized for one at a time. (no surge capability)

That is the point for a official requirement for the capability.  Without it, there is none.

Additionally, Skylab rescue was part of the early plans from the early part of planning

http://history.nasa.gov/SP-4011/part2c.htm

May 22 1969
"MSC reviewed plans for the development of mission operations documentation and presented the results of a joint MSFC/MSC study on the use of the CSM to rescue a malfunctioned LM/ATM."

http://history.nasa.gov/SP-4011/part3a.htm
December 23 1970
"An assessment of the feasibility of providing a crew rescue capability for Skylab was conducted by KSC, MSC, and MSFC during 1970. The study culminated in a NASA Hq decision to provide a limited rescue capability should return capability fail while the CSM were docked to the OWS. The rescue vehicle for the first two manned Skylab missions would be the next CSM in flow at KSC. Should a rescue call occur, the CSM next in flow would be modified so as to permit a five- man carrying capacity. It would be launched with a two-man crew and return with the additional three astronauts."

March 4 1971

A plan was devised to provide a rescue capability for SkyIab in the event the crew became stranded in the OWS because of failed CSM. The rescue capability was based on the assumption that the stranded crew would be able to wait in the Skylab cluster with its ample supply of food, water, and breathing gases until a modified CSM capable of carrying five crewmen could he launched. If a failure occurred which stranded the crewmen in their CSM, this rescue capability would not be possible.

The KSC rescue launch response time would vary from 10 to 45 1/2 days, depending on the transpired time into the normal checkout flow.

This is not an "LON"

[Chris Bergin]

The "5.5 Segment Ares I" thread introduced the suspicion that Ares I flights will need a rescue vehicle standing by for a Launch on Need (LON) flight.

There are zero references or requirements by CxP for LON standby with Ares/Orion. Kinda ironic someone's assumed that up based on nothing via the 5.5 seg Ares I thread, which is another assumption-only.

Questions ably answered and dismissed - and locked.