bloom can create the files you need, but in practice the process for getting into the "official" Debian or Ubuntu package repositories is more difficult than that. Most of the time there requires some manual tweaking of the resulting files. You can produce just the debian files like this:
$ cd path/to/package
$ ls package.xml # There must be a package.xml here
$ bloom-generate debian --os-name ubuntu --os-version precise --ros-distro hydro
==> Generating debs for ubuntu:precise for package(s) ['catkin']
No historical releaser history, using current maintainer name and email for each versioned changelog entry.
Package 'catkin' has dependencies:
Run Dependencies:
rosdep key => precise key
cmake => ['cmake']
gtest => ['libgtest-dev']
python-argparse => []
python-catkin-pkg => ['python-catkin-pkg']
python-empy => ['python-empy']
python-nose => ['python-nose']
Build and Build Tool Dependencies:
rosdep key => precise key
gtest => ['libgtest-dev']
python-argparse => []
python-catkin-pkg => ['python-catkin-pkg']
python-empy => ['python-empy']
python-nose => ['python-nose']
cmake => ['cmake']
==> Placing templates files in the 'debian' folder.
==> In place processing templates in 'debian' folder.
Expanding 'debian/changelog.em' -> 'debian/changelog'
Expanding 'debian/control.em' -> 'debian/control'
Expanding 'debian/rules.em' -> 'debian/rules'
$ ls debian
changelog compat control rules source
In the above example I did this for catkin, and the resulting files in the debian folder will be a good start, but you will need to iterate on them before they are accepted into the debian repositories. Also, you must make sure all of your dependencies are in ubuntu first, so that means you cannot depend on other ROS packages.
I don't know what launchpad is but bloom is the right tool to publish your package in the Debian repositories which will make it available in Ubuntu (and other Linux distributions based on Debian).