So this is the first achievement most of you will get in the new zombie map, Ascension. It requires you to ride the Lander from each of the three platforms to the core. This can be done in solo and sets you up for the Space Race achievement also (However, you'd probably need at least two people for that).
Starting in the Generator Room, take out the zombies using the M1911 and knife till about round three. Then go through the door on the bottom level [750pts]. Then move upstairs via the staircase until you hit another door. Enter [1000pts] and follow the staircase to the last door [1250pts]. Here you are at the Controls for the Rocket. Turn the power on, which is on your right, and I'd recommend trying the mystery box for a better weapon.
Stay here for round 4-5. Be careful as the zombies will be coming from downstairs, the window near the mystery box, and also from the roof above. (At this point, if you are going for the Space Race achievement, I'd recommend going for headshots and knifes to maximise points). At the end of round 5, leave 2 zombies alive (I find it better than just one as the last one always speeds up when chasing you) and move downstairs to the ground floor, indicated with a 1 on the wall. Head left and open a door for [1250pts]. Straight ahead is a staircase leading up to one of the platforms that I'll be calling Platform B. To the left, following the path, there is a door [1000pts] which ends up at a area with a pool of water and a Perk machine. To the right in this area is another door [1250pts] which leads to another lander platform, Platform C.
If you have managed to open these areas with your current points, head back to Platform B, call in the lander and finish off the last zombies. At the start of Round 6, camp the top of this area, keeping in mind the windows to the left and also up the stairs on the right. Even in solo, you should be able to lock down this area with a decent automatic weapon. If you have any trouble, use the lander [250pts] as you need to anyway. At the end of the round, leave 1-2 zombies alive and go back to the main building you started at.
From the ground floor, this time exit right and open the door [1250pts] and then immediately right up the stairwell, into another room and up the stairs directly in front of you. Open the door [1000pts] and here you are at Platform C. You now have access to all 3 Lander platforms. Now ride the lander once from each platform [250pts x 3 = 750pts] and you will be transported back to the core.
After you activate the last one, you will receive the achievement and 35GS.
This will give you the ability to launch the rocket from the controls next to the power switch, which will then open the Pack a Punch area!
If you are struggling with points at all, remember to repair windows and use the pistol to get body shots before slashing to maximise points! The total needed to unlock doors and use the Lander three times is 9500pts!
Best of Luck!