Yes, Hwy 146 is a good road and takes you to the end of NASA rd 1 in Seabrook, note NASA rd 1 is being converted into the elevated NASA parkway, when I last drove through the area 3 or 4 years ago they had completed the western end of the parkway between I-45 to just west of the space center. I am not sure when / if it will be extended to Hwy 146. I don't know if you are planning on driving your RV, but you should be aware that the space center museum has pay parking, I am not sure about RV parking and even for cars it was around $8-10 the last time I was there. As to getting there, consider Hwy 73 from Orange to Winnie, TX, my mother in law lives in Lake Charles and works for a company in Houston (tele-commutes 90% of the time) and she always skips the Beaumont area of I-10 where construction is going on using this route, and claims it is faster)