Q&A: Mars Mission Aborts Near Mars

[Danderman]

Okay, I will assume that the initial missions to Mars will plan to land, survive on Mars until an Earth launch window, refuel, and then return to Earth, as a baseline.

[sdsds]

But, there isn't a lot out there on missions using Starship.

Because there are no public entities, governmental or corporate, planning such a mission.

 - NASA: public, but not formally planning it;
 - SpaceX is planning it, but is privately held.

NASA tells us what, by law, they must. There are no laws about what SpaceX must tell us.

[Danderman]

https://www.cnbc.com/amp/2024/01/31/voyagers-starlab-space-station-buys-spacex-starship-launch.html

The Nanoracks space station will launch on Super Heavy. Someone posted about this being an expendable Starship.

[Danderman]

"Phase 1" is really only valid prior to TMI. After that, there's not enough fuel  to flip around and return to Earth, they're committed to either going to Mars or orbiting around the Sun to return to Earth."

After TMI, return to Earth is easy, just de-accelerate a tad.

The farther from Earth, the more difficult the return.

[Danderman]

"The time for the return trip in such trajectories are indeed lengthy.  The entire aborted mission would be very roughly as long as a successful conjunction-class Mars mission."

If the Mars Starship carries enough consumables for an entire mission, including living on Mars for some months, and then return to Earth, then abort back to Earth would be possible if Starship is close to Mars when a malfunction occurs.

[Danderman]

Someone posted earlier about using Venus in a swingby maneuver to return to Earth, and someone else responded that thermal issues would preclude that.

For a Starship design for both Mars and Earth re-entry, it may be the case that thermal issues may not loom so large.

[laszlo]

Someone posted earlier about using Venus in a swingby maneuver to return to Earth, and someone else responded that thermal issues would preclude that.

For a Starship design for both Mars and Earth re-entry, it may be the case that thermal issues may not loom so large.

Earth re-entry (Mars too, for that matter) involves a large but limited duration heat pulse. Only the heat shield and outer layers of the structure get heated up. Once SS is landed, the heat input is gone and the collected heat can be radiated away, as well as being conducted into an atmosphere. While SS is disposing of the unwanted heat it is grounded, mostly empty of fuel and not trying to do much.

For a Venus mission the heat is continuous, not a pulse. The structure is heat-soaked and radiation into a vacuum is the only disposal mechanism. In the meantime, all systems need to remain operational at the higher heat levels.

In terms of stress and survivability it's the difference between a sprint and a marathon.

[Danderman]

https://www.thespacereview.com/article/4510/1

Jeff Foust wrote about a Starship Venus mission. Not too many technical details, though.