Are there any studies or technology envisioned for Mars entry and landing without a parachute?

Question

Are any space agencies examining the possibility of a Mars landing without a parachute?

It wasn't clear to me if the use of the HIAD (Hypersonic Inflatable Aerodynamic Decelerator) would eliminate the need for a parachute, especially for landings at higher elevations.

It’s hard to beat parachutes. They are almost an optimal solution. They’re light weight, can be stored compactly, add lots of drag, and are reliably deployable. To improve upon any one of these metrics usually sacrifices one or more of the others. — Paul, Apr 24 '20 at 19:58
SpaceX is planning to landing the Starship on Mars without a parachute. — Dan Hanson, Apr 24 '20 at 20:24
@DanHanson good answer! I hope you don't mind that I added a bit to it. — uhoh, Apr 25 '20 at 04:43
I can't remember Wherner von Braun's little booklet "The Mars Expedition" (illustrated by Chesley Bonestell) talking about parachutes. The idea was to use a very-large-winged glider, landing like a plane. Then put the tip in vertical position and take off again. — David Tonhofer, Apr 25 '20 at 10:29

score 6 · Answer 1 · edited Apr 25 '20 at 01:23

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Yes

The SpaceX Starship is designed to land on Mars by aerobraking, then using retro-propulsion to land. After re-fueling, Starship would then be able to take off again and return to Earth. No parachutes in the mix at all.

SpaceX had planned for the first flight in 2022, but that's very unlikely at this point. More likely, the first Mars trip might happen in 2024 or 2026. There's more about that in answers to SpaceX and propulsive landing on Mars — what just happened? (and why?)

edited Apr 25 '20 at 01:23

uhoh

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answered Apr 24 '20 at 21:09

Dan Hanson

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I’m surprised to hear that it makes absolutely no use of parachutes whatsoever. To be sure, the large mass delivered to the surface certainly requires a variety of techniques like retropropulsion and aerobraking. I’m just surprised to hear that parachutes would not be used at all. Wouldn’t that incur an unnecessarily hefty thermal protection system mass penalty? – Paul Apr 25 '20 at 05:20
Elon Musk's goal is to make humanity a multi-planetary species. Part of that goal is to be able to land on pretty much any object in our solar system. Since some of those don't have an atmosphere (e.g. the Moon), they need to be able to land without parachutes anyway, so why waste time, money, and resources developing them? We don't know much about the TPS yet, and the design has changed multiple times. At one stage, Starship would "sweat" methanol through tiny pores in the stainless stell hull, but that was abandoned again. SpaceX are iterating rapidly, and can make even radical design … – Jörg W Mittag Apr 25 '20 at 07:45
… changes in a matter of months if not weeks, so we'll just have to wait and see. – Jörg W Mittag Apr 25 '20 at 07:45
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It is ambitious (possibly foolish) to expect a single vehicle design to accomplish both atmospheric and non-atmospheric entry/descent/landing. A good engineering principle is to keep the design as simple as possible. Parachutes are simple and should be used whenever applicable. I don’t see how atmospheric landing would be practical without one. – Paul Apr 25 '20 at 15:49
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@Paul Parachutes do nothing about the thermal protection needs--if you're going fast enough to care about thermal protection you're going too fast for a chute. Mars landings are heat shield -> parachute -> rockets. – Loren Pechtel Apr 25 '20 at 21:46
Red Dragon would also have made its landing without parachutes. In this case, a vehicle that originally had them would have been modified to land without them as part of making it capable of landing on Mars. – Christopher James Huff Apr 25 '20 at 21:52
@Paul: In every probe that's been sent to Mars, the vast majority of the braking is done before the parachutes even open, so it's not actually that difficult to replace them with propulsive landing. Really, our use of parachutes has been down to our lack of confidence in propulsive landing on unprepared ground and unwillingness to change something that works...they're heavy, and getting them to meet the required performance is very difficult (which is why the ExoMars mission has been delayed until 2022). – Christopher James Huff Apr 25 '20 at 21:58
@ChristopherJamesHuff: At some point the extra mass of the entry system (with tps & payload) is so great that retropropulsion is definitely necessary. Would it be correct to say that if we need to add the mass of a retropropulsion system anyways, we might as well get rid of the parachutes because they are not useful enough (i.e. not enough drag to be beneficial compared to the retropropulsion) for a thin atmosphere like Mars? – Paul Apr 25 '20 at 22:09
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@Paul: It's probably close, and there's also reliability to consider. The most reliable component is the one you're able to remove entirely. Parachutes may have a reliability advantage if you lack confidence in propulsive landings (there is a possibility that a botched landing after a parachute descent could still leave a lander able to communicate and do some science), but once you master those, the range of missions where parachutes are optimal is at least greatly reduced. – Christopher James Huff Apr 26 '20 at 13:10
Parachutes can also serve other purposes beyond simple braking. For example, stretching out and orienting tethers so the deceleration rockets can fire at a distance from the surface with the payload dangling below (https://mars.nasa.gov/MPF/mpf/edl/edl1.html). MSL managed without this (and also did more braking with the parachutes before releasing the skycrane than most missions have), but needed to fire rockets while the tethers were being extended (https://mars.nasa.gov/resources/3309/final-minutes-of-curiositys-arrival-at-mars/?site=insight). – Christopher James Huff Apr 26 '20 at 13:21

Are there any studies or technology envisioned for Mars entry and landing without a parachute?

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