is that domain newly designated to be a nameserver? Or did the IPs for ns1/ns2 change recently?
First, don't confuse resolving with being authoritative. Your /etc/hosts could contain a hostname of rocketflow.com and get the right IP, regardless of the configuration of the DNS server.
First, I think the glue for your DNS servers isn't set correctly. If this domain never had a nameserver running, then, you need to get your registrar to put the IPs into the master zone file -- they should have a procedure for this. Because those records are missing, the world really cannot find the servers. I don't have access to a zone.info file, but, I would bet this is the first issue.
If they had previously been authoritative DNS servers in the past, then that diagnosis is wrong.
As for your second results of ns1 and ns2 having valid dns entries on the 2nd machine, the problem still there is one of the zone probably not being configured correctly.
mcd@tsavo:~$ host ns1.rocketflow.com 130.94.75.209
ns1.rocketflow.com does not exist at 130.94.75.209 (Authoritative answer)
mcd@tsavo:~$ host ns1.rocketflow.com 130.94.75.210
ns1.rocketflow.com does not exist at 130.94.75.210 (Authoritative answer)
If those are indeed the IPs for ns1 and ns2, they should at least answer authoritatively for that domain. They do answer authoratively, but, know nothing about ns1/ns2. Again, this MIGHT mean that /etc/hosts is configured with the hostnames and IPs. That says to me that the zone file is incorrect.
mcd@tsavo:~$ host rocketflow.com 130.94.75.210
rocketflow.com A 198.104.132.29
because of this response, we must conclude that the zone file is incorrect, but, the server does appear to be answering authoritatively and is saying that ns1/ns2 don't exist in its copy of the zone.
you appear to be missing
ns1 IN A 130.94.75.209
ns2 IN A 130.94.75.210
from your zone file.
Barring that, it is possible the registrar issue might be playing into this, but, with the zone file broken, it is hard to say.
Now, it does seem really odd that
www.rocketflow.com and rocketflow.com have extremely different IPs from ns1/ns2, but, they are both owned by Verio, so, it could just be different allocations.
I would get the IPs set in the zone file first. Once that is done, we can see if the glue records are indeed correct in the zone.info files maintained by verisign.