# How much delta-v does it take to get from a Lunar Transfer Orbit to a Near Rectilinear Halo Orbit around the moon

There has been a lot of talk of NASA putting a Lunar Gateway in a Near Rectilinear Halo orbit around the moon, but I don't actually know how much delta-v it takes to get there. Most delta-v maps I can find have the delta-v for a lunar transfer orbit burn (about 3.2 km/s from Low Earth Orbit) and the delta-v for breaking into Low Lunar Orbit from the transfer burn (about 0.82 km/s), but I don't know how much it takes to go from the transfer orbit to a Near Rectilinear Halo orbit. I assume it takes less that Low Lunar Orbit, but how much less?

The delta-v from LEO to NRHO is 3.95 km/s.

The flight time is 5.33 days with an impulsive departure from LEO at 3.124 km/s and an NRHO capture impulse of 0.829 km/s.

• Reading the article you linked, it is surprising to me that the cost to go from NRHO to Low Lunar Orbit is so high (0.73 km/s), since that is not much less than the amount of delta v you’d need to capture into Low Lunar Orbit from a transfer orbit in the first place instead of going to NRHO first. I guess that’s the price we pay for having our stuff in a nearby stable orbit May 17, 2020 at 17:22
• Hmm, it’s weird, the first source listed on that page (ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150019648.pdf) has a diagram that seems to suggest a 428 m/s capture delta-v, while the second source (engineering.purdue.edu/people/kathleen.howell.1/Publications/… ) claims a capture delta-v of 829m/s as stated in your answer and in the linked article. Given the limitations of Orion’s performance I think 829 m/s seems high but I don’t know how to account for the discrepancy. I think I might email NASA or Tim Dodd or someone May 17, 2020 at 17:43
• (The third source doesn’t discuss delta-v and the fourth source has nice diagrams with delta v labels to various lunar orbits but doesn’t include NRHO) May 17, 2020 at 17:54
• engineering.purdue.edu/people/kathleen.howell.1/Publications/… May 19, 2020 at 0:37
• Here's a more direct source to the NRHO delta-v requirements: engineering.purdue.edu/people/kathleen.howell.1/Publications/… May 19, 2020 at 0:38