Why is the SpaceIL Lunar Lander doing a one-way trip? Is that a common project to do nowadays, to send landers to Mars and the Moon without returning them?
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asked Mar 12 '19 at 14:17
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3$\begingroup$ Maybe because of the smaller budget that drove to have a lighter payload which did not allow for extra fuel? $\endgroup$ – KingsInnerSoul Mar 12 '19 at 14:20
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3$\begingroup$ This is a "show" mission more than a scientific mission, and a successful landing and walkabout it sufficient to make it a spectacular success for a first time deep space mission for this agency. Returning to Earth is just an opportunity to fail, whereas success may bring interest in a follow-on mission. $\endgroup$ – uhoh Mar 12 '19 at 14:34
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12$\begingroup$ It is very common for Mars landers not to return. In fact, it is ubiquitous. $\endgroup$ – Organic Marble Mar 12 '19 at 14:38
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2$\begingroup$ One way trips are and have always been the norm in space exploration. The few sample return missions (mentioned by @Hobbes) are very much the exceptions. $\endgroup$ – ben Mar 12 '19 at 19:03
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A one-way trip is much simpler and much cheaper than a return mission.
- a return mission is more complicated because it has to do more
- a return mission is much heavier (because of the extra systems, and the fuel needed for the return capsule) which means it needs a bigger launcher which is more expensive
We have had no sample return missions from any planet. There were a few from the Moon (Apollo and Luna), and a few from objects like asteroids and comets (e.g. Hayabusa).
The SpaceIL mission is a small, low-cost mission done as a technology demonstration. A return mission would have cost 10x more.
