JPL maintains an interesting list: Near-Earth Asteroid Delta-V for Spacecraft Rendezvous

Let's display how Delta-V depends on perihelium q=a*(1-e)

(Graphs are done with R package and the related ggplot function)

**Neo with q <=1**

Delta-V (km/s) vs q (AU)

delta-v = -7.3q + 11.4 when q<=1

**Neo with q> 1**

Delta-V (km/s) vs q (AU)

delta-v = 4.6q - 0.5 when q>1

**Three "bands" for Delta-V**

As stated in the JPL page, for comparison, Delta-V for transferring from Low Earth Orbit to rendezvous with Moon and Mars:

- Moon: 6.0 km/s
- Mars: 6.3 km/s

1) moon-like (Delta-V <= 6.0 km/s)

2) mars-like (Delta-V <= 6.3 km/s)

3) beyond-mars (Delta-V > 6.3 km/s)

**Neo with q <=1**

Delta-V (km/s) vs q (AU)

**Neo with q > 1**

Delta-V (km/s) vs q (AU)

We can look at the neo distribution in every Delta-V band:

**Neo with q <=1**

**Neo with q >1**

**Ultra-low Delta-V Neo**

I often read that these neo are considered as a particular interesting target for spacecraft rendezvous missions because very little energy is needed to reach them.

This is a graphical display for neo with Delta-V <= 4.5 km/s:

These ultra low Delta-V neo are just a tiny fraction of the neo population.

This is their proportion:

As known, one of the problems with these neo is that it is very difficult to find relative bright (and thus big) asteroids.

The graph below shows all the ultra low Delta-V asteroids with H (mag) <= 23 showing that only three neo of this group have H (mag) <= 22. They are:

Designation | Delta-V (km/s) | H (mag) |
---|---|---|

2011 CG2 |
4.112 |
21.5 |

2001 US16 |
4.428 |
20.2 |

2002 NV16 |
4.460 |
21.4 |

**(1999 RQ36) Bennu and ("similar?") Neo**

Delta-V for Bennu: 5.087 km/s

H (mag) = 20.9

See also:

http://en.wikipedia.org/wiki/101955_Bennu

http://astro.mff.cuni.cz/davok/papers/bennu_osiris_maps2015.pdf

If we give a look at asteroids having Delta-V and H at least comparable (or better) than those of asteroid Bennu, target of the OSIRIS-REx mission, we can find a few other ones.

Bennu is shown at the top-left corner of the image.

Bennu is shown at the top-left corner of the image.

Of course, Delta-V is not the only parameter used to decide whether an asteroid is a good candidate for a sample return mission (physical characteristics, a well known orbit and an appropriate rendezvous time are certainly other fundamental aspects!).

Once said this, I would be interested to know if some of the other asteroids shown here are candidates for similar missions.

In fact, I found an interesting link showing the earth-centric orbit view of many of these asteroids

In fact, I found an interesting link showing the earth-centric orbit view of many of these asteroids

Kind Regards,

Alessandro Odasso

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