To go to Mars, do a backflip at Venus

[su27k]

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

Some, though, see a value of doing a Venus flyby mission as a precursor for going to Mars. A July 2022 workshop by Caltech’s Keck Institute for Space Studies, attracting participants from NASA, industry, and academia, focused on the science and exploration prospects for a Venus human flyby mission, leading to a report published in September.

A central argument to a human Venus mission is that it offers an intermediate stepping-stone between human missions to the Moon, lasting weeks or months, and a Mars mission with a round trip of as much as three years. “As part of an integrated strategy toward a first mission to Mars, a dedicated mission to Venus has the potential to be a productive and beneficial mission that could expand our human spaceflight operations knowledge in a stepwise manner starting at and around the Moon, continuing to Venus, and then at Mars,” the workshop report states.

Such a mission, lasting one to two years, would test out many of the technologies needed for a cruise to Mars and back, as well as the various human factors issues associated with missions far longer than expeditions in Earth orbit or at the Moon. A Venus mission, the report concluded, “affords the ability to close knowledge gaps and buttress confidence in technology, concept of operations, and human adaptability before setting out on a Mars expedition.”

The report: Meeting With the Goddess: Notes from the First Symposium on Venus Science Enabled by Human Proximity

[su27k]

Haven't read the report, but this sounds like Venusian science community trying to piggyback on NASA human exploration directorate's crewed Mars mission so that they can do some Venusian science, otherwise the concept makes no sense.

The irony is NASA is doing very little to enable a crewed Mars mission, so there's nothing to piggyback on. I think Venusian science community would be better off planning dedicated Starship mission to Venus.

[Harry Cover]

Manned Venus flybys (and Mars too) have zero science value. Or even zero value overall.

It's a 60 years old idea - vintage 1963, EMPIRE / UMPIRE - that staunchly refuses to die. This was already proposed in the 1980's, for Mars too.

Blackstar would told you it is a matter of young people not being aware of previous similar proposals from decades in the past.

In passing, Stephen Baxter in his 1996 alt-history novel Voyage, has one of the characters promptly shooting down the silly idea - poking fun at it.

The usual caveat: why risking human lives across the inner solar system just for a few hours close from Venus or Mars ?  Going so fast like a cannonball, nothing useful can be done except perhaps taking photos - alas, unmanned probes since Mariner 2 have been there since 1962... 60 years ago.

Going only in orbit barely justifies, but flybys ? forget them.
Will never get funded.
- Mars at least has Phobos and Deimos as interesting places to explore - before the surface.
- no such chance for Venus ! No moon and a hellish surface. No place to land there !

[personal rambling ON - If only Venus had a moon - even a small potato like Phobos / Deimos would be interesting. Then imagine if Venus had a monster moon like Earth - a Ganymede or Titan - size satellite, now THAT would have been a cool place to explore. Alas, it doesn't exists. personal rambling OFF]

Bottom line: if you send humans outside Earth, the real deal are surfaces, as in the Moon or Mars or Phobos or Deimos. By this metric, Venus is doomed. Hellish surface and no moon, so no place to land there ! A pity because it is closer than Mars, for sure.

[Harry Cover]

Now of course the above applies to the NASA way of doing human exploration since 1961 and Alan Shepard suborbital hop. Public money allocated by Congress, you know the music.

On the contrary - if BFR-Starship ever becomes a true and tried "spaceborne 747 spaceliner" then of course, some billionaire could quite literally charter one such vehicle to a Venus flyby: on their own private money.

Think of Dear Moon & Polaris Dawn - except to Venus. Okay, sure, if one billionaire wants to get a close glance at Venus, of course he can fund that. Think of Denis Tito Inspiration Mars (I KNOW it wen't nowhere - but you get the point nonetheless !)

[AmigaClone]

Now of course the above applies to the NASA way of doing human exploration since 1961 and Alan Shepard suborbital hop. Public money allocated by Congress, you know the music.

On the contrary - if BFR-Starship ever becomes a true and tried "spaceborne 747 spaceliner" then of course, some billionaire could quite literally charter one such vehicle to a Venus flyby: on their own private money.

Think of Dear Moon & Polaris Dawn - except to Venus. Okay, sure, if one billionaire wants to get a close glance at Venus, of course he can fund that. Think of Denis Tito Inspiration Mars (I KNOW it wen't nowhere - but you get the point nonetheless !)

Granted, with #dearMoon and Polaris Project the billionaires in question are funding some projects that SpaceX already had likely considered, or that would fit within their company goals. A fly-by of Venus (or Mars for that matter) might not fit as well.

[Harry Cover]

Yup, the billionaire would be completely on his own. Then again, nowadays we have billionaires with some hundred billions in the bank account, so they surely have craptons of dollars to spend (did I said - WASTE ? no, I didn't !) on such projects

[colbourne]

Considering the high risks, I  see no value in a manned fly by mission of Venus.

I would like to see a mission (either manned or unmanned) to put a habitat in the clouds of Venus. This could be a one way manned mission if there were volunteers with enough supplies to survive there natural lifetime.

As has been said many times before, Venus is probably the only place where, if Earth was wiped out we could maintain a breeding colony without the risk of low gravity causing birth defects. Probably also  having a  civilisation on Mars  and the asteroid belt for raw materials.

[daedalus1]

Considering the high risks, I  see no value in a manned fly by mission of Venus.

I would like to see a mission (either manned or unmanned) to put a habitat in the clouds of Venus. This could be a one way manned mission if there were volunteers with enough supplies to survive there natural lifetime.

As has been said many times before, Venus is probably the only place where, if Earth was wiped out we could maintain a breeding colony without the risk of low gravity causing birth defects. Probably also  having a  civilisation on Mars  and the asteroid belt for raw materials.

That discussion has occurred in other threads and I totally think it's pie in the sky.
Don't reopen it here, this is about a Venus flyby.

[sebk]

Flyby is indeed meh. Once could use it for some teleoperated probe (or a couple), so it wouldn't be zero value, but see below...

If anything, upgrade Starship or non-Starship HLS or DearMoon Starship and take advantage of the fact that propulsive capture into HEVO (High Elliptical / Highly Elongated Venus Orbit) as well as subsequent TEI from such an orbit both require small dV. 2x0.7km/s is good for a 4 month transit or 2x1.5km is good for 100 days interplanetary pass.

Fly there, spend several months in orbit, and drop some teleoperated probes: Lifetime of a probe below 40km in the atmosphere would be counted in hours, so remote control with sub-second delay would allow things like smartly picking up samples greatly improving scientific output from those few hours stay. And if we detect any surface activity a probe could be dropped there in days thus obtaining good science. When the time comes fly back to the Earth and if you're using HLS derivative -- do a propulsive capture into HEEO, but if flying reentry capable vehicle just come and land.

That's a mission doable using relatively small modifications of Moon exploration tech in current development, and with smaller dV requirements than a Moon landing. So the development cost would be moderate, expected scientific outcome reasonably larger than the outcome of all robotic Venus exploration to date, and on top of that it'd be a nice human exploration enhancement. That makes more sense than some meh flyby.

[arezn]

It seems that nobody oaid attention to
Back-Flip:

The Keck workshop, though, found a middle ground between the flyby and the orbital Venus missions. That alternative, dubbed the “Venus Back-Flip” by workshop participants, would involve two flybys of Venus, with the mission staying close to Venus between the two.
 The first flyby would send the spacecraft out of the ecliptic, loitering over one of poles of the planet (from the perspective of Venus), before making a second flyby to go back to Earth.
 Such a maneuver, formally called a “pi transfer,” was used by Cassini to adjust its orbit around Saturn, but had not, to the recollection of workshop participants, ever been proposed for a crewed mission.

backflip
An illustration from the report of the “Venus Back-Flip” maneuver that would allow a crewed mission to perform two close approaches to the planet, spending nearly six months in the vicinity of Venus.

And what about Back-Flip for Mars?

[Robotbeat]

It’s not necessary for Mars, but we should absolutely do it some day because it’d be cool. And we could do telerobotics for surface robots.

With the improvements in space access and spacecraft costs, we can afford such missions even if the return would not be as high as Mars.

[Phil Stooke]

It's hard to imagine anything more mind-numbing than spending 6 months in the vicinity of Venus.

[arezn]

What is the vicinity of Venus?

...   the vicinity of Venus, which the report defines as being
!!!    within one light-minute of the planet:
!!!  close enough to allow for teleoperation of probes in the planet’s atmosphere or on its surface.

[deadman1204]

It's hard to imagine anything more mind-numbing than spending 6 months in the vicinity of Venus.

Spending several years on the way to saturn? Given, it would be better once you get there.